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mrnon H. c:.ggnx,'or' rumour 'nnwxpnxgflsssrcnonjro SOSTON' Russian sse's ameras:*r'abssasrnosa me somet m RUBBER sons ron Beer s hi1) saws.

s ouses];- of Letters rat'e'nt'.

Patented Oct. 14, 49,;9.

No Drawing. Continuation application Serial No." 89,255, filed May-22, 1916, and a division of application Serial No. 107,853, filed July 6,1916. which is a continuation? application Serial No. 878,935,?fllgd December 24, 1914. This application filed May 6, 1919. Serial No. 295.168.

To all whom. it may concern: i

Be it known that I, Mrnon H. CLARK, a. citizen of the United States, residing at Pelham, county of \Vestebester, and State of New York, have inventedcertain new and useful Improvements in Rubber Soles for Boots amrblhoes, of which the following is a full, clear and'exact description.

This invention relates to rubber soles for boots and shoes and has for its primary object to provide a superior article at a reduced cost. This application is a division of my application Serial No;107,853' and a continuation of my application Serial'No ln manufacturing molded rubber soles the usual method is to fill the mold with the rubber compound and to vulcanizethe sole while in the mold. Molds suitable for this purpose are expensive and haveto be re; placed by other molds to meet the change in styles of footwear. The molding process furthermore is slowso that a Comparatively small output of soles requires a large expenditure for the molds. sole has the further disadvantage that a thin flash of rubber is formed on the peripherv of the sole between the mold sections, which is not. removed without considerable trouble. I

In the manufacture of, soles bymy method, the rubber may be mixed with suitable compoumlsrin the usual way and when Themolded in proper condition it is Sllbjflctfid to theaction of calender rolls to' produce the desired sheet from which the soles are cut or stamped. There are many well known rubber compounds suitable for use in the manufacture of soles and m a lication is not limited to any particu ar compound. For instance, in the publication entitled, The illmm-fm'fure of Rubber, by Adolf Hell and Dr. \V. Escln-edition if-1909, page 81, may he found compounds for soles containing among other lngredionts rubber gu'ln,

reclaimed rubber, carbon-black, litharge,

whiting, sulfur, barytcs, etc. There are however, such numerous and well known compounds that nothing further needb'e said here relating thereto.

rubber boots or shoeshrhhr'in the soles are vulcanized to the uppers, the stock is 'sheeted out substantially as above mentioned and the soles are cut fromthe shoet 55 usually in a transverse directiontliereoil The soles are often of varying thicknes's i'n the dircctionof their length, an'd'to accoilr' plish this the calender roll is coniposc'd nfcircumferential bands of correspomliugly; 3r varying diameter. The sheet of stock issu ing from such a alender will thus lie-com: posed of bands of varying tliiclniess"rn11- ning -longitudinally, thereby making itneccssary to out the soles so that tlidir an lengths will run transversely of the sheet of stock, in order to produce the desired Vii'ri'f ations in-the thickness of the sole atthc toe, instep, and heel portions thereof." Thlr usual practice in handling such stock'is "town permit the sheets to rest for a suite: ll? period of time after they have been fornted by the calender'ing machine to permitthctn' to shrink and to'assume permanentor noi' :nal conditions. The custom in most riibli'r factories is to permit the compounded-rub berstock to rest for an appreciable one after it'has been milled andprior its" 25* -ing placed in the warming rollsivhichjis the usual step preliminary to the sheetin gg Q of the stock by 'thecalender rolls. The stock is also permitted to rest over night after it has been calendered, after which it' cedu re as it provides a ready moansof m'iii closely determinin in advance the'illtimillld sizes which the so es will assume and more-positive results. While the std kdii 10o ing its restperiod has assumed pe-mason condition in so .far as the green jsheet is concerned. it is usual lmwever', nae-a v M H the vulcanizing process the sole in i't's 'tra'i S In the manufacture of -ri1bbe1"soles for formation 'from the green to the yiilca'iliz ii 10b ist-ate assumes a further shrinkt'tge tlep'en shrinkage, which is mostly longitudinally of the sole, when the sole is cut transversely of the sheet.

' ing out my invention,

Usually sheeted stock has greater strength longitudinally. and greater flexibility transversely, in this regard resembling very much the nature of a structure having a grain or fiber running longitudinally. In the carrying out of mymethod the soles have'been psually cut transversely of the sheet, that is to say, the length of the sole runs transversely of the sheet so that the sole possesses greater strength transversely and ater flexibility longitudinally. These con itions are well adapted to soles and or calendered sole advantages not possessed by a molded sole.

The smooth rolls ive the sole an irregu- Iir variation in thicfiness, the differences in height being separated by wavy lines running transverse y, of the sole. The irregularities are most manifest adjacent these wavy lines and give ,the sole the appearance of having whatmight be termed a pitted surface, the uneven. portions being some- -what inthe nature of flakes imperfectly ads hering to the body of the sole and sometimes partly separating therefrom so that difficulty may in extreme cases be experienced in 'se 'urely cementing the sole to an adjoining surface, such as the welt sole of the shoe.

In ap lying the cut or calendered soles to rubber oots and shoes, the usual practice has been to attach the sole to the shoe in ,its 7 or unvulcanized state and then to sublectj" the. entire. article to the vu'lcanizin heat; method, however, is not we] adapted for shoes or boots having leather uppers as the leather will not withstand the d of heatrrequired for-vulcanizin the 1 compound.

111 i soles. Therefore, whenever in her soles'jiave ,beeniused' upon leather footwear theinolded sole has-been resorted to. .gWhi'le'the extent-of the unevenness or me ularity of'the surface of the -calendered so e ducing the uneven flaky or pitted surface commonly designated in rubber factories as a fish-scale surface. I have found that if the rolls can procure a firmer grip into the rubber this unevenness may be regulated as de sired or reduced to a minimum. In carrytherefore, I may when desired, provide one orboth of the calender rolls Wit a gripping surface, preferably by knurling the surface, although it is obvious that many other engraved designs may be resorted to.

Where smooth rolls are exclusively used, the surface of the stock is quite irregular, the irregularity depending somewhat upon the nature of the compound used, as

give to a cut some do ree the action of e pitted surface will not be so prosurface,

already been mentioned. Such soles may be salable in certain sections and adapted for certain uses, such as lumbermens boots and for.other rough usages where an attractive appearance is not sought. Furthermore where only one of the rolls is smooth and the other knurled as described above there will obviously be two surfaces formed, the smooth roll reducin the pitted surface and the knur ed roll the engraved surface. The knurled roll will however, influence to the smooth roll, so that t nounced. Where both rolls are knurled both sides of the sole will. present an engraved although usually the wavy or fishscale a pearance is in evidence in combination with the knurled surface, but it is reduced to a minimum as above mentioned.

While the knurled appearance presents a surface more attractive for high class or dressy footwear, my invention is obviously in its broad aspect not limited to such a surface, but in its broadest hase com rises a vulcanized sole having t e natura calendered surface, the words natural calenis somewhat dependent'upon the nature of the ingredients forming the rubber compound, and the temperature at which the calender rolls are run, I believe the p tting 1s primarily-due to an alternate pu ling and slipping action of the rolls u on the rubber the rolls angles it is rawn therefrom by the rollsinto the spaeebetween" out at the opposite sideas asheet, the rolls,

on account 0 their smoothness-have a parthat e drawin of the rubber from "the bank is not uni arm; which results in pro- Theeom undis anke'd against.

tial slipping action on the rubber surface so them and travels derail being used in the sense that the vulcanizing process is so carried out that the finally vulcanized sole will not have lost the rface characteristics which the calender rolls have imparted to it regardless of what these characteristics may be.

- In accordance with an important feature of my invention, I provide face of which possesses the-characteristics of a sole, the sur-' the sheet issu ng from the calenderin machine; that is, a sole having a nature surface. Prior to my invent1on,so"far as I am aware, when vulcanii'zedapart from the shoe,

or polished surfaces substantially 120 rubber soles have invariably been vulcanized tached condition. I thus reserve the calendered structure pomess I by the sheet.

' Because of the vulcanization of the solo in a free and unrestrained condition, the

particles of the material constituting the sole, being unrestrained, do actually, during vulcanization, flow or move, about and accommodate themselves'to 'each other in such a manner as to result in producing a suerror article.

The 'sOlc therefciie has a sur ace, the particles of which are self-distributedand the particles of the sole are distributed in accordance with the normal or substantially free or unrestrained flow thereof. This not only preserves the natural,

smooth rolls.

usual manner upon mixing rolls.

calendiared surface of' the sole, but ohtains, such a, distribution of particles throughout the sole as to improve the product.-

A sole 'made by the use of knurled rolls is characterized by having a substantially uniformly even surface in the sense that it does not possess the irregular haphazard unevenness of the sole made by the use of hen it is desired to provide a sole having an entirely smooth surface, the knurls or other design may be removed by boiling or otherwise treating the-surface. In such case, the design may be made so 30 small, that it can be removed with but little trouble, whereas, to buff down the surface of a sole made by the use of smooth rolls would require considerable tim and trouble and represent, considerable loss of rubber.

'35 inasmuch as the buffing 15 performed after the sole hasbeen vulcanized.

In the practice of myinvention in its most refer Ld manner, the rubber is com- 'poun( ed wit 1 the desired ingredients in the formed into sheets by passing it between calender rolls maintained at suitable temperatures and engraved or not, as desired.

The sheeted rubber 'is then permitted to rest in the usual manner, and is finally out or stumped transyersely to form tbe soles, which are placed in an unconfined condition.

upon shelves. These are placed in a vulcanizer and e fluid pressure, preferably of ca'r-' to bon dioxid as, and heat applied to efi'ect graved rolls are used, hnv-a regularly even surface on surfaces winch are the counterthe vulcanization. The soles thus formed are homogeneous throughout and possess reater stren 'th transversely and greater flexibility longitudinally, and where gem part of the design upon the roll or rolls.

' While I prefer to cut the sole transversely from a single sheet, it me be built of any so desired number of plies o the .green stock,

the grain of the various plies running in the ,eame er' in difl'erent directions inany desired manner, the several plies being taken It is then from the some or different grades of stock. Where the soles are cut transversely of the sheet the calendered rolls may be varied in diameter atdifferent portions to provide greater thickness of stock at any desired parts of the sole, as for instance nt'the too or heel portions as is the usual practice in. such articles. The lllbldfilflslfick may be plied together in the sheet form or the severa] sheets may be, first cut to form the laminiltions and tl'lesefinully superin'lposcd to form the sole. In either case the several plies are preferably brought into intimate association by means of pressure as by rolls or resses.

aving thus described my invention, what I claim and desire to protect by Letters Patent is:

1. An unattached, vulcanized, rubber sole for boots and shoes comprising rubber-conmining maternal having a natural, calendered surface.

2. An unattached, vulcanized rubber sole for boots and shoes consisting of rubber-' containing nniterial having a wholly transverse, fibrous structure rendering said sole of greater transverse than longitudinal strength. 1 I

.3. An unattached, vulcanized rubber sole for boots and shoes comprising rubber-eon tuining material having greater transverse than longitudinal.strength and greater longitudinal :than transverse flexibility, and having a natural, calcndcred surface.

4. Au uimttachcd, vulcanized rubber sole .for boots and shoes comprising rubber-contullling material having a natural, preserved, cztlendercd surface, and being of greatest strength in a transverse direction and of greatest flexibility in a longitudinal direction, said sole being of substantially homogeneous structure throughout.

Signed at New York, county of New York, and Stateof .Ncw- York, this 3rd day of May, 1919.

MYRON H. CLARK. 

